Lehr for glassware



Feb. 14, 1950 u as. MERRILL LEHR FQR GLASSWARE Filed Nov. 23, 1945 g Invan for:

mm w mw mv mw V (2H7 HM, m h r a m N aw a: k v w WV m 1 0|. N E Q wm S Sg Q m f Q m 2 Dg'zald/GMerrill Attornqy Patented Feb. 14, 1950 LEHR FORGLASSWARE Donald G. Merrill, West Hartford, Conn, assignor toHartford-Empire Company, Hartford, Conn., a corporation of DelawareApplication November 23, 1945, Serial No. 630,332

13 Claims.

This invention relates to the art of annealing glassware and moreparticularly to improvements in lehrs of the type having an elongatetunnel through which the ware is moved and in which a heating passage isprovided at the bottom of the annealing portion of the tunnel and issupplied with hot products of combustion, as from a burner. An airconducting pipe is provided in this portion of the tunnel adjacent tothe heating means and has discharge orifices from which jets of air aredischarged directly into the tunnel. The heating means serves to radiateheat directly to the ware thereabove and also to preheat the airsupplied by the air pipe in the tunnel. The jets of preheated air aredischarged from such pipe at such places and in such directions as toset up desirable circulatory currents in the tunnel atmospheresurrounding the ware. The temperature gradient of the ware during itspassage through the annealing portion of the tunnel of the lehr willthus be controlled in part by the heat radiated thereto from theunderneath heating means and in part by the circulatory currents in thetunnel. Since the products of combustion do not contact the ware in thistype of lehr, any desired fuel, including oil, may be used.

A lehr f the character above described is disclosed in my Patent No.2,133,784, of October 18, 1938, for Method of and apparatus forannealing glassware. The present invention provides an improvement overthat lehr.

According to the present invention, the heating apparatus and the airconducting and discharging apparatus in the lehr tunnel have novelfeatures of construction and arrangement which enable them to performtheir several and cooperative or combined functions in a highlyefficient manner. These apparatuses may be installed in a lehr whichpreviously had been openfired and therefore had required the use of agaseous fuel and a plurality of burners so as to convert such anopen-fired lehr into a muffled heating-air circulating lehr of the typeabove described. In the latter, a liquid fuel and the products ofcombustion produced by a single liquid fuel burner may be utilized tosupply all the additional heat required to set up and maintain thedesired temperature gradient in the ware during its passage through theannealing portion of the lehr tunnel. The walls of the parts ofconducting apparatus are caused to pass directly beneath and up the farsides of some of these heat radiating parts so as to pick up additionalheat before they join the circulatory currents in the tunnel.

The arrangement of cooperative jets of preheated air and heat-radiatingcombustion products-conducting parts is novel and advantageous in thatit serves to effect adequate further heating of the jets of preheatedair in an improved manner and also controls the temperature gradient ofthe ware in the overhead portion of the tunnel and the heat-radiatingaction of the longitudinally extending heat-radiating surfaces of theheating apparatus. Preheating of the air in an improved way is aided byarranging heat conductive portions of the air conducting structure sothat they are in effect coils. These coils are located in heat exchangerchambers at the bottom and sides of the tunnel at a substantial distancefrom the ware-entering end of the latter. The products of combustion,which by this time have lost considerable heat, are brought to thesechambers and caused to travel back and forth therein in heating relationto the coils to heat the air in the latter before the spent products ofcombustion are permitted to pass out of the heat exchanger chambers to asuitably located exhaust passage. The arrangement just described has ahigh efficiency in the use of the heat produced by the operation of thesingle burner.

Other novel features and advantages of the invention hereinafter will bepointed out or will become apparent from the following description of apractical embodiment of the invention, as illustrated in theaccompanying drawings, in which:

Figure 1 is a horizontal section of the annealing portion and afragmentary portion of the subsequent, cooling portion of a lehrequipped with structure of the present invention, the vie-w beingapproximately along the line ll of Fig. 2;

Fig. 2 is a generally longitudinal vertical section approximately alongthe line '22 of Fig. 1; and

Fig. 3 is "a transverse vertical section approximately along the line3--3 of Fig. 1, the parts on top of the lehr tunnel being omitted.

Figs. 1 and 2 show, in a somewhat diagrammatic manner, what may betermed the annealing section, designated 1, of an elongate,substantially horizontal lehr tunnel, generally indicated at 2 in allthe views. The annealing section I of the lehr tunnel extends from itsfront or ware-entry end, indicated at 3 in Fig. 2, to approximately theplace along the tunnel at which there is an upward jog 4 in the tunnelbottom. The annealing section l of the lehr tunnel is so termed becausethe ware undergoing treatment in the lehr may have its temperaturecontrolled and regulated during passage through this portion of thetunnel so as to be lowered from an upper annealing temperature-at whichstrains in the glass of the Ware will be relieved to a lower annealinglimitat which the glass of the ware has become sufficiently rigid topreclude further molecular rearrangement therein. Below the lowerannealing limit, permanent strains cannot be introduced into the warewhich, however, may still require controlled further cooling for theremoval of temporary strains and so that the ware may be cooled to atemperature suitably low to permit handling of the ware soon after itleaves the lehr tunnel. The lehr tunnel that is partially shown in Figs.1 and 2 will, of course, have a cooling section, which -may=belike thatdisclosed in my aforesaid Patent No. 2,133,784, through which the warewill be transported and subjected to further cooling after leaving theannealing section I. This cooling section-is represented in the drawings(Figs. 1 and 2) by the fragmentary portion thereof indicated at 5.Further illustration and description thereof are not required since alehr tunnel havingan annealing section equipped with the improvementfeatures of the present invention may also include any suitable knowncooling section, equipped with any suitable known ware coolingprovisions.

The ware to be annealed will be carried through the lehr tunnel on theupper stretch B of an endless, woven-wire belt 7, only a portion ofwhich is shown since both it and the means for operatively supporting,guiding and driving itare in well-known and wide-spread use in tunnellehrs'. Itis sufficient herein to state that the. upper stretch 6 of theware conveyor 7 slides on a horizontal supporting and guiding metallicframework 8, Figs.- 2 and 3, which may rest at spaced points onsuitablerefractory supports,

including the upstanding pillars 9 on the tunnel bottom, Figs. 1, 2 and3, and blocks II] on the refractory top H, Fig. 2, of a heating chamber,hereinafter described, that is located in the lower part of the forwardportion of the lehr tunnel.

The tunnel walls may be constructed of any suitable, known materials,arranged and supported in any suitable known manner, all as well knownin the art. The tunnel has a through passage comprising a portion I2extending through the annealing section I of the tunnel and a furthersection 1 3 in the succeeding section of such tunnel. The passage 12 isopen at the front of the lehr tunnel, at 3, Fig. 2, to afford clearancefor theware (not shown) on the lehr conveyor, which of course willtravel in the direction tocarry the ware into the front end of andthrough the tunnel passage.

The heating apparatus provided by the present invention is located inthe annealing section of thelehr tunnel, mainly below the lehr conveyorsupporting and guiding framework 8. Such heating apparatus comprises aheating chamber comprising a combustion compartment or space I 4, Figs.1 and 2, which, as shown in Fig. 1, extends the full width of the frontend portion of the tunnel passage l2 at the bottom thereof and isprovided at one end with a burner port I15, formed in one of the sidewalls of the tunnel, with which a burner I6 is operatively associated.

The combustion space I4 has a rear wall I! which extends transversely ofthe tunnel from the side wall of the tunnel that is provided with saidburner port toward but not to the opposite side wall of the tunnel,whereby a restricted opening or passage [8 is provided at the rear ofthe end portion of the combustion space 14 opposite the burner betweensuch combustion space and a more rearwardly located space or compartment19 in the aforesaid heating chamber. The space or compartment [9 alsomay occupy the full width of the lower portion of the tunnel passage.Its continuity is interrupted at intervals by refractory pillarsarranged in transverse rows, one comprising right and left hand pillars20, another right and left hand pillars 2| and an intermediate pillar22, and a third comprising the transversely spaced pillars 23. Thesepillars not only serve as supports for the refractory top H of theheating chamber but as bailles by which the heated products ofcombustion which pass from the combustion compartment is through theopening I8 into the space l9 are dispersed or distributed throughout thelatter space and are retarded more or less in their flow to rightandleft hand rearwardly directed ports or passages 24 in the rear Wall25, Fig. 1, of such space. The space l9 of the heating chamber thereforemay be termed a heated productsdistributing space or compartment. Thearrows in the heating chamber, as shown in Fig. l, indicate in part theflow of the heated, products and the distribution thereof in suchchamber as. they pass to the ports or passages 24.

From the space [9, the heated products; of combustion pass through therear ports or passages 24 directly into theforward ends oflongitudinally extending rig-ht and left hand similar heating ducts 26.These may have light gauge walls of a refractory material having goodheat conducting properties or they may be made of any other suitableknown material that is sufficiently heat resistant and conductive. Theducts 26 have a partially flattened or oblong shape in cross-section.See Fig. 3. They may extend for the greater part of the length of theannealing section of the lehr tunnel. They are supported at intervals soas. to be. close to' the side walls of the; tunnel but spaced therefromas well as from the tunnel bottom. The major transverse axes of theseductsextend transversely of the tunnel. In the example shown,v theductsextend through suitable, closely fitting openings 2'! in thepillars9', by which the ducts are supported as above described. The.cross-sectional configuration ofthe ducts and the manner of theirsupport provide substantial advantages in the assembly of elementsprovided by the invention, as hereinafter will become clear.

The ducts 26 discharge their gaseous contents at their rearward endsinto inlet ports 28 in the front walls of a pair of right and left handbottom heat exchanger chambers 29. These are located in the bottom partof the rearward portion of the tunnel passage I 2 and togetherext'endthe full width of that passage, having a common inner side wall 30, Fig.1, at approximately the longitudinal median line of the lehr tunnel. Thechambers 29- have spaced, overlapping or staggered transverse partialpartitions or baffles which extend from-the outer side walls of thechamber, as indicated at 3| and 32, respectively, and from the innersidewall ofsuch chamber, as

indicated at 33. In consequence of these baffles,

the products of combustion passing through the inlet ports 29 into thechambers 29 travel back and forth in such chambers along horizontalzig-zag or sinuous paths, as indicated by the arrows in such chambers,until they arrive at the rearward portions of the chambers. The productsof combustion then may leave the chambers through outlet ports, one ofwhich is shown at 34 in Fig. 1, so as to enter vertical heat exchangerchambers 35 in the side walls of the tunnel. Each of these side heatexchanger chambers 35 is provided with spaced, overlapping or staggeredvertical partial partitions or baffles, as shown at 36 and 31,respectively, for one of such chambers in Fig. 2, whereby the productsof combustion entering each such side chamber will travel verticallyupward in the rear portion thereof to the upper part of such chamber,thence downwardly between the bafiles 36 and 31 to the lower portion ofthe chamber and then upward again in the forward portion .of suchchamber to a final discharge space 38 at the top of the chamber, asshown in Fig. 2. From the final discharge space 38, the products ofcombustion will enter a branch exhaust pipe 39, there being two of thesepipes 39, one for each of the two discharge spaces 38. Such branchexhaust pipe has a portion 49 which is in effect a Venturi tube. Aneduction air pipe 4| discharges into the branch exhaust pipe below theVenturi portion so that an effective draft will be set up in the branchexhaust pipe. There are, of course, two of the eduction air pipes, onefor each branch pipe 39. The branch exhaust pipes 39 may convergetogether to form a single final exhaust pipe 42.

The air preheating and circulating apparatus may comprise a blower 43,located at the top of the tunnel structure. A rearward air dischargepipe 44 of the blower may be divided at 45 to provide a pair of rightand left hand branch air pipes 46. Each pipe 46 may supply air underpressure to the eduction air pipe 4| hereinbefore mentioned. Inaddition, each branch pipe 46 leads to a header within the upper part ofthe corresponding side heat exchanger chamber 35 adjacent to the forwardwall of the latter. One of these headers is indicated at 41 in Fig. 2. Aset of vertical air pipes 48, four in the example shown, conduct airfrom the header 4! downwardly in the front part of a side heat exchangerchamber 35 to a header 49 in the bottom part of such chamber. The header49 is connected at 50 to a second bottom header 5|. From the latter,another set of air pipes 52 extend vertically between the bafiies 36 and31 to a second top header 53 in the chamber 35. From the top header 53,another set of air pipes 54 extends downwardly to a third bottom header55. The latter is connected at 56 to a fourth bottom header 5! which isoperatively connected to a set of four horizontal air pipes 58 in therear part of the adjacent bottom heat exchanger chamber 29. The pipes 58connect to a rear inner header 59 in the chamber 29. The header 59 alsois operatively connected by a second set of four horizontally extendingair pipes 60 to a header 60a in the outer side portion of such chamber,see Fig. 1. The header 60a. is also operatively connected by a secondset of horizontally extending pipes 6! with an intermediate header 62 atthe inner side of the chamber 29. The header 62 is connected by a secondset of horizontal pipes 63 to a front header 64 in the outer side of thechamber. From the header 64, another set of pipes 65 leadsto a frontinner side header 66.

The arrangement of headers and connecting pipes constitute connected airconducting coils in the communicating bottom and side heat exchangerchambers.

From the headers 66, longitudinal air pipes 61 extend through the frontwalls of the bottom heat exchanger chambers 29 forwardly in the lowerpart of the tunnel passage 12 between the heating ducts 26, as best seenin Fig. 1. At intervals along their lengths, the pipes 6'! dischargejets of air, as indicated at 68, laterally toward the heating ducts 26.In the example shown, the jets 68 are directed in a slightly downwardlyinclined direction laterally toward one or the other of thelongitudinally extending heating ducts at places intermediate adjacentsupporting pillars 9. The preheated air supplied by these jets will passlaterally directly across the lower surfaces of the supported portionsof the ducts between adjacent pillars and thence upwardly between thesides of these portions of the ducts remote from the air pipes and theside walls of the tunnel, as indicated by arrows in Fig. 3, meanwhileextracting heat from such ducts. At their forward ends, the pipes 61 areprovided with upwardly stepped or offset laterally turned dischargepipes 69 which may be integral portions of the pipes 61 or, if formedseparately, may be operatively joined thereto in any suitable knownmanner. The discharge pipes 69 are closed at their extremities, asindicated at 19, and discharge generally forwardly directed jets of airH over the heat-radiating top i I of the main heating chamber, as shownin Fig. 1.

The blower 43 may have a forwardly directed air discharge pipe 12 whichis provided at its extremity with an air nozzle 13, Fig. l, suitablyassociated with the burner 16 and the port l5 to support combustion ofthe fuel discharging from the burner and within the combustion space [4.

The operation and some of the advantages of the illustrative embodimentof the invention just described will be readily understood. Since theproducts of combustion produced by the operation of the burner cannotreach the ware, a liquid fuel, such as a suitable fuel oil, may be used.Only a single burner may be required. The operation of this burner mayprovide the requisite heat in an efficient and economical manner whenthe burner is used in conjunction with heating and air circulatingprovisions, such as hereinbefore pointed out. The heating chamber mayradiate heat to the ware in the front portion of the passage I2 to bringsuch ware quickly to the relatively high temperature required for reliefof strains in the glass thereof. The heating ducts 26 also radiate heatto the ware and lose heat to the circulating air. The gases passingthrough the ducts 26 will be highly heated on entering such ducts andwill lose heat gradually and uniformly en route to the bottom heatexchanger chambers. In the latter, full advantage is taken of the heatremaining in such gases to preheat the air in the air conducting coilswithin such chambers. The air-preheating structure requires but arelatively small part of the length of the lehr tunnel, this because ofthe compact arrangement of air conducting coils and associate heatingprovisions.

The air discharging from the sides of the longitudinally extending airpipes 61 will pass laterally outward beneath and then upwardly at theouter sides of the relatively flattened or oblong heating ducts26andthus will scrub over the lower and outer side surfaces of these ductsbefore being directed upwardly by the side walls of the-tunnel passagepast the sides of the conveyorsupporting and guiding framework. Thepreheated air sup plied by the jets 58, which, on discharge'from the airpipes 6'1, may be too cool to be suitable for introduction into theware-containing portion of the tunnel, will be supplied with sufiicientadditional heat by the ducts 26 to be sufliciently heated for suchintroduction as such air passes'laterally outward beneath and upwardlyat theouter. sides of the heating ducts 2%. In the ware transportingpart of the tunnel passage, the air currents will be directed inwardlyto approximately the vertical median line of such passage and thendownwardly around and against the ware, through the open-work wareconveyor and its open-work supporting structure, and back to the airjets discharging from the pipes 67. The circulation is approximately asshown by the arrows in Fig. 3 and will be repeated so as to recirculateat least part of the air. Thus, the tunnel atmosphere will be circulatedand recirculated about and past the ware on the moving conveyor in theannealing section of the lehr tunnel. Desirable control and regulationof the temperature gradient of the ware passing through this section ofthe tunnel may thus be obtained.

The front jets H of preheated air are further heated by the top wall ofthe heating chamber. They then pass upwardly into the front part of thetunnel passage so as to oppose ingress of cold air at the front of suchpassage. Some of these jets H, as the end jets of the series, may beturned slightly toward the side walls of the tunnel, as shown. Some ofthe air from these jets may pass out of the tunnel through the openfront end of the tunnel passage. The remainder of such air may moverearwardly until it comes under the influence of a transversecirculation, with which it will then combine.

The invention is not limited to the details of the illustrativeembodiment of the invention herein particularly described as manychanges therein and modifications thereof will readily occur to thoseskilled in the art.

I claim:

1. Apparatus for annealing glassware, comprising an elongate tunnel,means for conveying glass? ware therethrough, mufile means locatedwholly beneath the path of the ware in the tunnel for, passingrelatively highly heated gases longitudinally of the tunnel beneath andin heat-transfer ring relation with the ware passing therethrough, saidmufile means having a delivery end located a substantial distance alongthe tunnel from the front end thereof, heat-exchanging means operativelyconnected to the delivery end of said mufiie means and located in saidtunnel in part below and in part at a side of the path of the ware, anair blower operatively connected to said heat exchanging means to supplythereto air to be preheated, and air conducting and discharge meansoperatively connected to said heat exchanging means to receive preheatedair therefrom and to direct such air into the tunnel.

2. Apparatus as specified in claim 1 wherein the heat-exchanging meansextends across the bottom of the tunnel and up the sides thereof.

3. In apparatus for annealing glassware, an elongate tunnel comprisingan annealing section extending from the front end of the tunnel for asubstantial part of its length, an open-work conveyor for conveyingglassware through the tunnel along a path spaced above. the bottom ofsaid annealing section, heat exchanging means in saidannealing sectionof the tunnel, said heat exchanging means comprising a series ofconnected air conducting coils located in part beneath and in part at'aside of the path of the ware and heated media conducting meansconstructedand arranged to cause heated media passing therethrough toenvelop said coils, muflle heating means Within said annealing sectionextending from nearthe front end of the tunnel longitudinally thereoffora substantial part of thelength thereof and having a delivery endoperatively connected with said heated media conducting meansiof theheat exchanging means to supply heated media to the latter, and meansoperatively connected withsaid series of coils and extending in saidannealing section below said pathof the ware to receive preheatedairfrom said seriesof coils and to dischargejets of such air. intosaidtunnel.

4. In. apparatus. for annealing glassware, an elongate tunnel, means forconveying glassware through the tunnel, a muffle heating chamber-in thetunnel beneath the path of the ware, a heated media conducting ductoperatively connected with said muffie heating chamber and extending asubstantial distance in said tunnel below the pathof the Ware and inheat transferring relation therewith, heat exchanging. means in saidtunnel into which said duct dischargesheated media, said heat exchangingmeans including air conducting coils in position therein to receive heatfrom the heated media therein, and an air conductingpipe to receivepreheated air from said coils and to discharge-jets of the preheated airlaterally therefrom in the lower part of the tunnel across the bottomsurface of said mufiie heating duct.

5. Apparatus as specified in claim 4 wherein said duct-is substantiallyoblong in cross-sectional configuration and has its major transverseaxis approximately horizontal.

6. In apparatus for annealing glassware, an elongate tunnel, means forconveying glassware through the tunnel, communicating side and bottomheat exchanger chambers in. said tunnel, the former extending at a sideof the path of the ware and the latter being located below said path, aseriesof connected air conducting coils in said heat exchanger chambers,means operativelyconnected to one end of said series of coils to supplyairunder pressure thereto, mufile heating means-extending in said tunnelbelow the path of the ware to supply heated media to said bottom heatexchanger chamber, and means operatively connected to the other end'ofsaid series of coils to conductpreheated air longitudinally ofsaid'tunnel below the path of the ware and todischarge jets of the preheatedair into said tunnel.

'7: Apparatus as specified in claim 6 wherein said mufiie heating meanscomprises a duct having heat-radiating walls and of substantially oblongconfiguration in cross-section, said duct being located in said tunnelin positionto be scrubbed across its" bottom surface by jets of thepreheated air discharged in said tunnel, the major axis of said ductbeing approximately horizontal.

8. In apparatus for annealing glassware, an elongate tunnel comprisingan annealing section extending from the front end of the tunnel fora-substantial part of its length, means for conveying glassware throughsaid tunnel, a heating chamber in the lower part of said annealingsection .below-the'epath of the ware and adjacent'to the frontend' of ithe tunnel, heat exchanging means in the annealing section at asubstantial distance from said heating chamber, said heat exchangingmeans comprising a pair of relatively right and left bottom chambers inthe tunnel below the path of the ware and relatively right and left sidechambers in the side walls of the tunnel and respectively communicatingwith the right and left bottom chambers, a series of connected airconducting coils in each set of communicating side and bottom chambers,relatively right and left heating ducts extending in the lower part ofsaid tunnel below the path of said ware and respectively connecting theheating chamber with the right and left bottom chambers so as to deliverheated media to the latter, means connected to the ends of said coils inthe side chambers to supply air under pressure to said coils, and airconducting pipes operatively connected to the other ends of said coilsand extending longitudinally of the lower part of the tunnel forwardlythereof between said heating ducts, said air conducting pipes beingconstructed and arranged to discharge spaced jets of preheated airlaterally from their outer sides directly beneath and upward at the farsides of said heating ducts.

9. Apparatus as specified in claim 8 wherein said heating ducts areapproximately oblong in cross-sectional configuration, have their majortransverse axes substantially horizontal, and are spaced above thebottom and inwardly from the side walls of the tunnel at the placestoward which said jets of preheated air are directed.

10. Apparatus as specified in claim 8 wherein said heating chamber has aburner port and a liquid fuel discharging burner operatively associatedtherewith, and in combination therewith, a branch air supply pipeoperatively connected with the means for supplying air to said coils to10 supply air adjacent to said burner to support combustion of fuelsupplied by the burner.

11. Apparatus as specified in claim 8 and, in addition, exhaust meansoperatively connected with said side chambers, and means operativelyconnected with the means to supply air to said coils to also supply airto said exhaust means to aid a draft therein.

12. Apparatus as specified in claim 8 and, in addition, a pair ofoppositely extending, upwardly offset, lateral air discharge pipesoperatively connected at their adjacent ends to the forward ends of saidlongitudinally extending air conducting pipes, and closed at theirremote ends, said lateral air discharge pipes being constructed andarranged to direct jets of preheated air generally forward over the topof said heating chamber.

13. Apparatus as specified in claim 8 and, in addition, a pair ofoppositely extending, upwardly offset, lateral air discharge pipesopel'atively connected at their adjacent ends to the forward ends ofsaid longitudinally extending air conducting pipes, and closed at theirremote ends, said lateral air discharge pipes being constructed andarranged to direct jets of preheated air generally forward over the topof said heating chamber, the generally forwardly directed jets nearestto the side walls of the tunnel being turned slightly toward such walls.

DONALD G. MERRILL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,486,265 Pike Mar. 11, 19242,133,784 Merrill Oct. 18, 1938 2,335,128 Merrill Nov. 23, 1943

